JPH08984Y2 - Creeping corona discharge element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a surface corona discharge element used as an ozone generator or an ion generator.

[Conventional technology]

This type of creeping corona discharge element has a linear discharge electrode and a planar induction electrode on the surface and inside of a plate-shaped substrate made of ceramic, and high-frequency voltage is applied between these electrodes to generate a creeping corona on the substrate surface. This is what causes a discharge. However, when moisture is adsorbed on the surface of the ceramic substrate, conductivity is generated on the surface, corona discharge becomes unstable, and the amount of ozone and ions generated is reduced. Therefore, in order to stabilize the discharge in a high humidity atmosphere, there has been proposed one in which a heater wiring is embedded and heated inside a ceramic substrate (Shokai Sho 60-1437).

[Problems to be solved by the device]

However, in the case where the heater wiring is embedded inside the ceramic substrate, since the planar induction electrode and the heater wiring are extremely close to each other, corona discharge noise is induced in the heater wiring and the heater wiring functions as an antenna. However, there is a problem that electromagnetic noise increases.

In addition, the one with embedded heater wiring has a problem that the number of manufacturing steps is high and the cost is high.It is difficult to make a high resistance heater by printing technology and it becomes a low resistance heater, so a high voltage just rectified commercial voltage. There is a problem that it can not be used in 2 minutes to 5 minutes until the heater is heated and the corona discharge is stabilized and the specified ozone amount is obtained.
There was a problem that it took a long time for a minute.

The present invention has been made in view of the above problems,
It is an object of the invention to provide a creeping corona discharge element that operates stably in a high humidity atmosphere, is inexpensive, and has low electromagnetic noise.

[Means for solving the problem]

In order to achieve the above object, in the present invention, as illustrated in FIG. 1 of an embodiment drawing, a linear discharge electrode 3 is provided on a surface of a plate-shaped substrate 2 made of ceramic, and the inside of the substrate 2 is provided. A planar induction electrode 4 is buried in the linear discharge electrode 3
In a creeping corona discharge element 1 in which the planar induction electrode 4 and the planar induction electrode 4 are opposed to each other via a dielectric layer, a creeping corona discharge element 1 is provided in which a resistor 8 is attached to the back surface of the substrate 2. To be done.

Further, it is preferable that the resistor 8 has a positive temperature characteristic.

[Action]

With the creeping corona discharge element 1 configured as described above,
When the resistor 8 attached is energized, the temperature of the resistor 8 rises to heat the substrate 2 and evaporate the moisture adsorbed on the substrate 2. That is, the resistor 8 attached to the substrate 2 is used as a heater resistor. Since the resistor 8 is attached to the back surface of the substrate 2, the planar induction electrode 4 and the conductive portion of the resistor 8 are slightly separated from each other, so that the corona discharge noise is less likely to be induced in the resistor 8 and electromagnetic noise is generated. Get smaller.

Further, the resistor 8 having a positive temperature characteristic is used,
By using the resistor 8 for controlling the primary side current of the driving power source for discharging, more current is made to flow while the temperature of the substrate 2 is low, thereby actively causing discharge.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings. First
FIG. 1 is a front view of a creeping corona discharge element 1 according to the present invention, FIG.
The figure is a perspective view showing the upper surface of the creeping corona discharge element 1, and FIG. 3 is a perspective view showing the lower surface.

A linear discharge electrode 3 made of tungsten is provided on the upper surface of a flat plate-shaped substrate 2 made of high-purity alumina porcelain, and a planar induction electrode 4 made of tungsten is embedded inside the substrate 2 so that both electrodes are formed. 3 and 4 are provided so as to face each other with a dielectric layer made of alumina porcelain interposed therebetween and integrally sintered. A protective layer made of alumina is formed on the upper surface of the linear discharge electrode 3. The linear discharge electrode 3 is connected to a terminal 6 on the edge of the substrate 2, and the planar induction electrode 4 is connected to a terminal 7 provided in a hole on the back surface of the substrate 2. These conductive portions 3, 4, 6, 7 are formed by a metallizing technique.

On the back surface of the substrate 2, a rectangular cement resistor 8 molded with cement as a resistor is adhered with cement or the like. At this time, the lead wires 9 and 10 of the cement resistor 8 and the substrate 2 are separated by 2 mm or more. Cement resistance 8
For example, a material having a positive temperature characteristic, for example, tungsten is used as the resistance, and when the temperature is heated from room temperature to 80 ° C., the resistance value increases by about 20%.

FIG. 4 is a circuit diagram showing the driving power supply 11 for discharging. The positive electrode of the DC power supply 12 whose negative electrode is grounded is connected to the lead wire 9 at one end of the cement resistor 8, and the lead wire 10 at the other end of the cement resistor 8 is connected to the first capacitor 13 whose one end is grounded. . A shield wire 14 is used for connecting the cement resistor and the driving power supply, and the outer cover of the shield wire 14 is grounded on the power supply 11 side.

In parallel with the first capacitor 13, the second resistor 15 and the second
A series circuit consisting of the condenser 16 and is connected. The first capacitor 13 is connected to one end of the primary winding of the transformer 17, and the other end of the primary winding is a transistor.
Connected to 18 collectors. The emitter of the transistor 18 is grounded, and the base is connected to the connection point between the second resistor 15 and the second capacitor 16 via the diac 19. The diac 19 is an element that becomes conductive when a voltage higher than a predetermined value is applied, and here, a 30V element is used. One end of the secondary winding of the transformer 17 is connected to the terminal 6 of the linear discharge electrode 3 of the creeping corona discharge element 1, and the other end is connected to the terminal 7 of the planar induction electrode 4.

The DC power supply 12 has a relatively high voltage of 140 V, the cement resistor 8 has a high resistance value of 10 KΩ, and the first capacitor has a capacitance of about 0.1 μF.

The operation will be described based on the above configuration. FIG. 5 is a waveform diagram for explaining the operation of the driving power supply 11, showing the voltage 13a of the first capacitor 13 and the output voltage 17a of the transformer 17.

The cement resistor 8 acts as a resistor that limits the charging current of the first capacitor 13 and the second capacitor 16. When a voltage is applied from the power source 12, the first capacitor 13 and the second capacitor 14 are charged and the respective voltages gradually rise. When the voltage of the second capacitor 16 reaches 30V, the diac 19 becomes conductive and the base current is supplied from the second capacitor 16 to the transistor 18
18 is made conductive, and the electric charge charged in the first capacitor 13 is discharged all at once through the primary winding of the transformer 17. Therefore, a high voltage is generated in the secondary winding of the transformer 17, a high voltage is applied between the electrodes 3 and 4 of the creeping corona discharge element 1, and a creeping corona discharge is generated. Condenser 13, 16
When the discharge of is completed, the diac 19 returns to the off state and returns to the initial state. Then, the above operation is repeated again. The repetition frequency is about 500Hz.

The cement resistor 8 generates heat due to the charging current to the capacitors 13 and 16, and when the environmental temperature is 25 ° C, the substrate 2 of 15 × 40 mm
Is heated to about 80 ° C. Therefore, the moisture adsorbed on the surface of the substrate 2 evaporates, and the creeping corona discharge in a high humidity environment becomes stable.

Further, since the primary current of the driving power source 11 is controlled by using the cement resistor 8 for heating having a positive temperature characteristic, the temperature of the substrate 2 and the cement resistor 8 at the initial stage of power-on is kept low. The resistance value becomes low. Therefore, the charge / discharge cycle is shortened and the repetition frequency is increased to actively cause the discharge, and the charge voltage of the capacitor 13 is slightly increased to cause the strong discharge, improving the startability immediately after the power is turned on. . As a result, it takes about 5 minutes after the power is turned on for stable discharge in the related art, but in the present embodiment, it becomes stable within about 1 minute, and the starting performance is greatly improved. This effect was sometimes remarkable when the environmental temperature was low, as in the case where the surface creeping corona discharge element 1 was used as a deodorizing ozone generator for a refrigerator.

Further, in this embodiment, since the creeping corona discharge element 1 with the heater can be manufactured only by adhering the cement resistor 8 to the back surface of the substrate 2, it is cheaper than the conventional one in which the heater is embedded in the substrate 2. It can be manufactured.

Regarding electromagnetic noise, in the conventional one in which the heater is embedded in the substrate 2, it is necessary to separate the creeping corona discharge element from the antenna by 5 m or more in order to prevent the noise from entering the television receiver. On the other hand, a distance of 3 m was sufficient in this example in which the cement resistor 8 was attached. Furthermore, the lead wires 9 and 10 of the cement resistor 8 and the substrate 2 are 2 m.
The electromagnetic noise can be further reduced by keeping the distance more than m and using the shield wire 14 for the connecting cable between the cement resistor 8 and the drive power supply 11 and grounding the shield jacket on the drive power supply 11 side. It was By the above two measures, even when the creeping corona discharge element 1 is placed at a distance of 1 m from the antenna of the TV receiver, FM radio, and AM radio, the radio noise will not enter at all, and the level will be practically no problem. .

[Effect of device]

Since the present invention has the above-mentioned structure and the resistor serving as a heater is attached to the back surface of the substrate, it is possible to inexpensively provide a creeping corona discharge element having a high resistance heater. There is also an excellent effect that electromagnetic noise can be reduced.

In addition, a resistor using a resistor having a positive temperature characteristic is used for controlling the primary side current of the driving power supply, so that a strong discharge is generated when the substrate temperature is low at the initial stage of discharge, and immediately after the power is turned on. There is an effect that the startability of can be improved.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 1 is a front view showing a creeping corona discharge element, FIG. 2 is a perspective view showing an upper surface of the creeping corona discharge element, FIG. 3 is a perspective view showing a lower surface, and FIG. FIG. 5 is a circuit diagram showing the driving power source, and FIG. 5 is a waveform diagram for explaining the operation of the driving power source. 1 ... creeping corona discharge element, 2 ... substrate, 3 ... linear discharge electrode, 4 ... planar induction electrode, 8 ... cement resistance, 11
...... Driving power supply.

Claims (2)

[Scope of utility model registration request] 1. A linear discharge electrode is provided on the surface of a plate-shaped substrate made of ceramic, and a planar induction electrode is embedded inside the substrate to form the linear discharge electrode and the planar induction electrode. In a creeping corona discharge element opposed to each other via a dielectric layer, a resistor having a pair of lead wires formed in a three-dimensional shape is attached to the back surface of the substrate, and the pair of lead wires is attached from the back surface of the substrate. A creeping corona discharge element characterized by being separated. 2. A linear discharge electrode is provided on the surface of a plate-shaped substrate made of ceramic, and a planar induction electrode is embedded inside the substrate to form the linear discharge electrode and the planar induction electrode. A creeping corona discharge element in which a resistor having a positive temperature characteristic is attached to the back surface of the substrate in a creeping corona discharge element in which the two are opposed to each other via a dielectric layer.